**Note**This protocol is not exact. You will have
to add PVA in step 4 until the solution is clear and is slightly
less viscous than molasses. Refrigerate the beaker of gelvatol
overnight at 4 degrees, after step 5 and before step 6, and check
it in the morning to be sure that the viscosity is now that of
molasses. If it is, continue on to step 6. If it is too viscous,
add a little more glycerol to bring the viscosity down and then
go on to step 6. If it is not viscous enough, add more PVA with
heat and refrigerate for a few more hours to check the viscosity
before going on to step 6.